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TITLE:   GCN CIRCULAR
NUMBER:  8861
SUBJECT: GRB 090129: Swift detection of a burst
DATE:    09/01/29 21:20:29 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

H. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
P.A. Curran (MSSL-UCL), P. A. Evans (U Leicester),
N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara), J. A. Kennea (PSU),
N. P. M. Kuin (MSSL), C. B. Markwardt (CRESST/GSFC/UMD),
P. T. O'Brien (U Leicester), C. Pagani (PSU),
K. L. Page (U Leicester), B. A. Rowlinson (U Leicester),
P. Schady (MSSL-UCL), M. Stamatikos (NASA/ORAU) and L. Vetere (PSU)
report on behalf of the Swift Team:

At 21:07:15 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 090129 (trigger=341504). The BAT on-board calculated 
location is RA, Dec 269.092, -32.826 which is 
   RA(J2000) = 17h 56m 22s
   Dec(J2000) = -32d 49' 32"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a FRED-like
structure with a duration of about 20 sec.  The peak count rate
was ~7000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

Due to an observing constraint, Swift cannot slew to the BAT position. 
There will thus be no XRT or UVOT data for this trigger until
at least 03 Feb 2009. 

Burst Advocate for this burst is H. Ziaeepour (hz AT mssl.ucl.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

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TITLE:   GCN CIRCULAR
NUMBER:  8862
SUBJECT: GRB 090129: Swift-BAT refined analysis
DATE:    09/01/30 13:58:35 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
T. N. Ukwatta (GWU), H. Ziaeepour (UCL-MSSL)
(i.e. the Swift-BAT team):
 
Using the data set from T-120 to T+962 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 090129 (trigger #341504)
(Ziaeepour, et al., GCN Circ. 8861).  The BAT ground-calculated position is
RA, Dec = 269.105, -32.793 deg which is 
   RA(J2000)  =  17h 56m 25.1s 
   Dec(J2000) = -32d 47' 34.8" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.
 
The mask-weighted light curve shows emission starting at ~T-30 sec,
then a large-amplitude FRED peak that returns to background at ~T+70 sec.
T90 (15-350 keV) is 17.5 +- 2.7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.2 to T+27.0 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.88 +- 0.06.  The fluence in the 15-150 keV band is 2.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.00 sec in the 15-150 keV band
is 3.7 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/341504/BA/

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TITLE:   GCN CIRCULAR
NUMBER:  8897
SUBJECT: GRB 090129: Fermi GBM detection
DATE:    09/02/09 17:17:37 GMT
FROM:    Sylvain Guiriec at UAH  <sylvain.guiriec@lpta.in2p3.fr>

S. Guiriec (UAH) reports on behalf of the Fermi GBM Team:

"At 21:07:15.42 UT on 29 January 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090129 (trigger 254956037 / 090129880) which was
also detected by the SWIFT-BAT.
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 22 degrees.

The GBM light curve consists of a single peak with a FRED shape starting at
~T0-0.3s with a duration (T90) of about 17.2s (8-1000 keV).
The time-averaged spectrum from T0-0.3s to T0+15.1s is well fitted by a
Band function with Epeak = 123.2 +/- 44.8 keV, alpha = -1.39 +/- 0.13,
and beta = -1.98 +/- 0.14 (chi squared 373 for 374 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(5.6 +/- 0.7)E-06 erg/cm^2.
The 1-sec peak photon flux measured starting from T0+0.8 s in the
8-1000 keV band is 8.0 +/- 0.1 ph/s/cm^2.

The spectral and temporal analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."